Pressing the key combination Shift + F9 in a person's CRM window opens the following dialog:

Set where the entries are to be transferred and, if necessary, restrict the date field. Then confirm with OK.
All entries (in the selected period) will be deleted from the original person and will be displayed to the new person instead. Only the entry for the new creation of the person and the record changes remain with the original person.

Pressing the key combination Shift + F9 in the Project opens the following dialog:

Now you can mark the sub-entries (tick) (1) and then assign them to another project (3) via selection (2).