I can think of a way, success depends on the complexity of the geometry. Explode the polylines into lines, get the midpoints from the lines and find the closes lines, not the source line itself.

• Chopper to create lines with 2 vertices.
• CenterPointReplacer to convert to midpoints.
• NeighborFinder to find closes lines to points. Number of Neighbors to find = 2. Generate Closest Candidates List.
• ListExploder to go from list to features.
• Tester to remove all results with _distance = 0, these are the original lines.
• Now you have multiple widths. You can draw those using VertexCreators and the closest_base / closest_candidate attributes.

Added sample workspace.

Thank for attention. But it also works on balcony corners and i don't want that. Can you use the examples i attached?

I would exclude short lines from the analysis. Shorter than 0.3m worked fine for your samples. But feel free to experiment what works best yourself.

• LengthCalculator after the Chopper
• Tester after the LengthCalculator, _length > 0.3

This looks like it is works . Thank you