....descending from F360 to F320 initially.Tfc for further descent
is xxx at F300. Still acft goes thru F316 b4 climbing back to F320.Tfc is right below.Doesnt the TCAS show the TFC below?
You kind of answer your own question with that description.
Level busts happen. Either TCAS or an alert ATCO shouts, and the situation is (hopefully) recovered safely.
What does not happen is for flight crew to manage level change against the TCAS display. TCAS is a safety net. It is not a navigation aid, and use as such is strongly discouraged.