The integrated Time Machine function creates and makes available to you daily, weekly ... copies of the entire system, including large files using technologies such as "Hard linking" which is nothing more than marking files that have not changed or have been modified to share them between different copies and not having to re-copy everything with the consequent saving of space in addition to having several different copies over time.
However when they exist high volume backups You can reduce the number of them available if they are stored on a smaller disk or partition, so if we want to keep a greater number of different copies from different times we will have no choice but to be more selective by eliminating unnecessary files.
Some examples of these files could be movies that we are not going to watch again or files such as system images for a virtual machine that take up a lot of space and we are not going to use that instance again so we should not be interested in keeping it.
To be able to delete in one go instead of manually deleting said file copy by copy, we will simply move to the location where the file is saved and we will enter Time Machine and then with the secondary menu, click on the option to delete all copies of security of that particular file.
With this we will make sure that we can continue saving more backup copies at different times and at the same time we clean up those unnecessary files that only take up space.
More information - Disk Drill will be your perfect ally in the recovery of files and partitions