I .
to match or agree with sth :
This evidence ties in closely with what we already know.
II .
tie in (with sth) | ˌtie sth ↔ ˈin (with sth)
to link sth or be linked to sth; to happen, or arrange for sth to happen, at the same time as sth else :
The concert will tie in with the festival of dance taking place the same weekend.
—related noun tie-in