Create Element Geometryfrom list (rooms)

I am working on rooms. I did a filtering with string to object and then i used the filter by boolean mask.
But now my node Element.Geometry does not work anymore. Can i go back from string to geometry somehow?
Thanks for any advice

You seem to have done something wrong upstream.

Element.Geometry obviously wouldn’t work if you feed it numbers.
Ensure that you are feeding in Elements (Rooms, in your case) to the list input port of List.FilterByBooleanMask

It would help it you post a larger portion of your graph or/and the relevant file.

Hello Vikram,
yes you are right. I want to apply two filters (By Floor and Room Number) and than generate wall surfaces from the sum of these filters.
Thats waht happens to beginners, right?
Here is the whole screenshot, as a new user i cannot upload a file.


I am a dynamo beginner too. I am having a bit of trouble trying to figure out your end goal.
From what you have it appears you want to get all elements that have both parameters you called out. After you do that you would like to create a surface from it? If that is what you want try this adjustment in blue:

Or do you want a surface from the intersection of the 2 list? Then make this adjustment but before you connect it to the intersection node you must convert the elements from each filter to geometry (sorry didn’t draw lines correctly) :

After that … I am unsure how you want to make the surface. You are placing an intersection into a surface input. A good next step would be look at the surface nodes to see how to create a surface (ie, by patch, by surfaces, points, etc etc). I don’t know what geometry you started with to anticipate the type of geometry you will get from their intersection so really don’t know the next step.

Thank for reply. I am working on rooms. I want, for example to filter all living rooms on one level and create a new wall around the room, its actually a covering. After that i join the existing wall with the new one to cut out windows and doors. It works well when i dont use filters. I create a curve at the perimeter of the room which serves as curve for the new wall.

could you show what you had before the filtering?