As a Spec-Ops, place the mine where a group of Chimera will come from (i.e., Teleporter, doorway).
Unfortunately, XR-87 mines are often ineffective against Titans, mostly because it tends not to recognize them, probably due to their size or that they move so slow, as enemies. This means they won't detonate when they step on or near the mine.
|“||This ML-SPEC incendiary device contains a tremor-sensitive mercury switch that picks up seismic activity within a fixed area. Even the lightest footstep is enough to set off the device, making it SRPA's most dangerous proximity explosive to date.||”|