# Masking out one list from another

**URL:** <https://forum.dynamobim.com/t/masking-out-one-list-from-another/8303>\
**Category:** Uncategorized\
**Created:** [December 16, 2016, 6:01pm UTC](https://forum.dynamobim.com/t/masking-out-one-list-from-another/8303 "2016-12-16T18:01:48Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![cp\_questions](https://avatars.discourse-cdn.com/v4/letter/c/58f4c7/32.png) [@cp\_questions](https://forum.dynamobim.com/u/cp_questions)\
**Post date:** [December 16, 2016, 6:01pm UTC](https://forum.dynamobim.com/t/masking-out-one-list-from-another/8303/1 "2016-12-16T18:01:48Z")

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This seems like an easy problem, so maybe I’m overthinking it. I have a list of all project levels, and a list of levels that I want to mask out of the master list of levels. I’ve figured out how to do it, but I feel like there has to be a better way than my solution. The script I used below would need the user to manually add or deduct the level element, and then pair it with an _IndexOf_ node, and then feed it into the list of indicies to remove… Seems counter intuitive.

I’m hoping there is a better way 😐

 ![](https://us1.discourse-cdn.com/flex022/uploads/dynamobim/original/3X/4/6/467905fa3d2a9e0b1267f081afeb50898bf8995f.JPG)

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**Author:** ![Yna\_Db](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.dynamobim.com/yna_db/32/30641_2.png) [@Yna\_Db](https://forum.dynamobim.com/u/Yna_Db)\
**Post date:** [December 16, 2016, 6:19pm UTC](https://forum.dynamobim.com/t/masking-out-one-list-from-another/8303/2 "2016-12-16T18:19:13Z")

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Hello, the answer could be there:

> [@Filter one list using another list](https://forum.dynamobim.com/t/filter-one-list-using-another-list/7060):
>
> I know this is a variant of some other questions, but I’m new to this, and haven’t figured it out yet. I have list (imported from excel) of sheets I need to create - with sub-lists for sheet number, sheet name, and three custom parameters we need. From that, I can create the sheets by following any of several posted examples. But my script stops as soon as it gets to a sheet that already exists, so I want to filter my list of desired sheets to remove sheets that already exist. Creating the l…

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<div class="post-metadata">

**Author:** ![cp\_questions](https://avatars.discourse-cdn.com/v4/letter/c/58f4c7/32.png) [@cp\_questions](https://forum.dynamobim.com/u/cp_questions)\
**Post date:** [December 16, 2016, 6:31pm UTC](https://forum.dynamobim.com/t/masking-out-one-list-from-another/8303/3 "2016-12-16T18:31:40Z")

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same stuff I’ve been trying

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**Author:** ![T\_Pover](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.dynamobim.com/t_pover/32/19147_2.png) [@T\_Pover](https://forum.dynamobim.com/u/T_Pover)\
**Post date:** [December 16, 2016, 7:44pm UTC](https://forum.dynamobim.com/t/masking-out-one-list-from-another/8303/4 "2016-12-16T19:44:52Z")

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If there’s a common characteristic by which you can filter the levels you want to remove, then you could just do a string contains and search for that common chararcteristic.  
Otherwise to improve upon the workflow you already have:

 ![](https://us1.discourse-cdn.com/flex022/uploads/dynamobim/original/3X/2/8/2857f12a0a59c51f7a01587620ec978876d7b811.png)

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**Author:** ![Vikram\_Subbaiah](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.dynamobim.com/vikram_subbaiah/32/50797_2.png) [@Vikram\_Subbaiah](https://forum.dynamobim.com/u/Vikram_Subbaiah)\
**Post date:** [December 17, 2016, 1:53am UTC](https://forum.dynamobim.com/t/masking-out-one-list-from-another/8303/5 "2016-12-17T01:53:33Z")

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![](https://us1.discourse-cdn.com/flex022/uploads/dynamobim/original/3X/8/f/8f880b4bec41d1ebf5dde30e7ca1aabefd85c390.png)