It's hard to tell exactly what you are trying to do in your graph, but the python code moves the tag by a given vector. As you can see in the graph, one way would be to specify a start and enpoint, create a line by those to 2 points and then use Line.Direction to get the vector for the movement. Feed that into the python node and the tags should move accordingly.
EDIT: I see the tags are placed on section views, that might complicate things a bit. Check out this post as well: https://forum.dynamobim.com/t/tagging-walls-tag-location/1468/29