If you want to migrate dimension with more than 5,000 elements you can update the parameter MaximumElements in Pulse.cfg. In the screenshot we can see that the value is still 5,000.
More information in the following Help section:
WARNING: Increasing the value may cause Pulse to run out of memory if it is a very large value so use with caution.
If the dimension has more elements than the MaximumElements value, when you migrate this dimension from a source instance to a target instance, the dimension will be created in the target instance without any elements, then to populate the dimension, you can run a TI at the end of a migration package: