Backup Options: How i can do an automatic delete of old backups?

Hello,
i hope you can help me with an TrueImage Problem. 

I would like to make a backup on my NAS every day.

Monday 01 -> Fullbackup
Tuesday 01 to Sunday 01 -> incremental backups
Monday 02 -> fullback again
Tuesday 02 to Sunday 02 -> incremental backups again

As far as so good, the daily backups works perfectly. 
Because the space on my NAS is limited, I would like that after the fullbackup on Monday 02, the backups Monday 01 to Sunday 01 are deleted. 
So on on Monday 02 only the fullbackup Monday 02 is on my NAS. 
This deletion does not work. Have tried several settings, the currently are (see attachment)

if it is not possible to delete the backups Monday 01 to Sunday 01 in one slide after the full backup Monday 02, then a daily deletion would suffice.
So a possible option is:
when fullbackup Monday 02 done -> fullbackup Monday 01 is deleted
when incremental backups Tuesday 02 are done -> incremental backup Tuesday 01 is deleted
and so on

Thanks for helping
With friendly regards
Manfred

Thanks for your help.