This is not possible in Project for split tasks. Instead, make the two
parts of the task you're splitting into separate tasks and link them as you
see fit. If it seems like a hassle, in truth it probably turns out that
this is a more accurate model of reality anyway. A "task" is a block of
work that produces a specific single deliverable. If you look at the
workflow of the your tasks in question, I'll bet the first part of the task
produces a deliverable which is handed off to the second task you want to
link in. That task, in turn, modifies it some way and then hands it back to
the remaining part of the split. An example - I write a report and give the
draft to an editor. The editor reviews it, suggests changes, and then sends
it back to me for revision. There really are 3 distinct deliverables
there - first draft, marked up draft, and final report. So it's really 3
tasks - write draft, edit draft, final rewrite - and not just 2 - write
report and edit report, with the writing task being split to allow for the
time editing. If you look at it closely I expect yours is a similar
situation.
