hI @mairh_tsek
Yes its possible, the examples I have shown below use fucntions from the steel tab. The only thing to note is when you start using these they change the Beam to a steel fabrication element and some normal functions become disabled (which is why your method might not have worked) all info can be seen here - https://knowledge.autodesk.com/support/revit/learn-explore/caas/CloudHelp/cloudhelp/2020/ENU/Revit-M...
I used either the Saw cut flange and changed the face it was cutting to

Or the contour cut and then sketch out the cut needed

Ive also made a short screencast showing how I did this modelling - https://autode.sk/3S9NpJG
Rob Merriman, Technical Specialist / Principal Structural Designer, OLG
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