Hi,
sorry no, not as long as those 3D-solids are "one-in-another" or at least overlapping.
The chance you have is to use <CTRL>-<CLICK> to select one of the 3D-solids that are part of UNION, then move that part away from the other part. And when the parts are not overlapping you can use command _SOLEDIT with options _BODY ==> _SEPERATE. (in the menu it's called "Seperate".

Just to make sure: the subobject handling can only work when SOLIDHIST was on.
- alfred -
------------------------------------------------------------------------------------
Alfred NESWADBA
ISH-Solutions GmbH / Ingenieur Studio HOLLAUS
www.ish-solutions.at ...
blog.ish-solutions.at ...
LinkedIn ...
CDay 2026------------------------------------------------------------------------------------
(not an Autodesk consultant)