Some bare TDR waveforms can be found here:
The fifth one shows a few small reflections caused by taps, followed by an unterminated end.
The ninth one shows a splitter in use (probably on coax), with reflections for the 2 legs.
In raw terms, I'd expect a TDR to be able to show reflections from every termination of a line.
However, while this ought to apply to bare lines, I don't know how they'd apply to a BT line that properly terminates in a master.
I imagine that a filter (such as an SSFP) does a good job of hiding any taps that occur behind it ... which should be fine. Taps behind filters are good. Taps before filters are the bad ones.