split up

split up
1. to divorce; end a relationship;
2. to divide, to go in two different direction —

Example 1: Misha and Marya split up after years of fighting over their finances.

Example 2: The teacher split up the two boys on the playground because they always argued over who would be captain of the team.

Example 3: The policemen split up in order to find the robber.

see also
[call it quits]