Odoo v16, Enterprise.

Let's say someone owns a company with three divisions that he treats as separate companies (C1, C2, C3).  As owner of the company, he would like to assign tasks on various projects relating to the three companies.  Is there a way to assign the task while in, say, C1, to someone working on a project in C3 or is it necessary to go into C3 and assign the task from there?  If the owner wants to create a multi-company project, is there a way that representatives from all three companies can look at the same project (assign tasks to the project, update timelines, etc.)...without going into a specific company to work on the project stored there (the same project would be visible from all three companies)?