"Not your average clothes peg holder" Bumper Trim Repair:~
 

Volvo 240 corner bumper trim & other: ~
The above trim pieces are usually made in stainless & plastic or black metal.
The black plastic sections can come away from the metal making it difficult to fix back into the body clips- particularly if the plastic comes away at the locating points.
I had this problem on a couple of pieces so decided to fix them- I did consider Polyurethane adhesive/sealant but this tends to get quite messy.
The product that also works is super glue (Toolstation HV used)
Make sure the surface areas for the plastic & metal are free from dirt or grease- waxoyl or similar.
Run a bead of the glue onto the surfaces paying attention to the part that slides into the body clips plus any other loose sections.
A working method is to lightly clamp the parts together with clothes pegs-see photo.
The above has worked well and quite easy to get a decent repair.
Trust it helps.
Bob.

Would make a nice Christmas present for the wife- oops!