Question
Do I need previous incremental backups to restore later incremental backups?
Answer
No, you only need the incremental backup that you intend to restore.
This is possible because each incremental backup contains hardlinks to the files that did not change from the last incremental backup. Any file that did change will be copied normally. This allows the files that are the same between backups to only be stored on the disk once but be available to all backups that use that file. The file will only be removed when all backups that use it are removed.
For example, the backups below contain hardlinks to the same .bashrc file as it did not change between backups, as indicated by the inode number.
[root@10-2-35-196 ~]# ls -i /backup/2022-01-*/accounts/ACCOUNT/homedir/.bashrc
920861 /backup/2022-01-22/accounts/ACCOUNT/homedir/.bashrc
920861 /backup/2022-01-23/accounts/ACCOUNT/homedir/.bashrc