Majority write concern in multi region

for a multi region cluster with 3 regions and 3:3:2 node distribution, the majority write concern will act as local to the primary region like if write operation is successful to 2 nodes in region 1 or will it wait for for completion of write to 5 nodes i.e. confirmation from cross region node that the write is complete?

You can have up to 7 voting members, so majority count is 4. Apart from the primary node, at least 3 others (any 3, same region or not) will have to acknowledge the writes before a response can be returned to client.