I seem to recall that if a positional coach is in final year of contract at another team, I can offer him a co-ordinators role at my club. But when I click on the guy's name there doesn't seem to be anywhere where an contract offer can be made.
if that team has given the coach a new contract in that season he's not eligible to be poached. Otherwise you can offer any positional coach a coordinator or head coaching job and they will accept.