PSU patches are cumulative. We have latest 184.108.40.206.2 PSU Patch 18090046 for 220.127.116.11 OMS, you should apply that patch.
To know the list of bug fixed in this PSU look at the readme or here is the direct MOS link- https://updates.oracle.com/Orion/Services/download?type=readme&aru=17311825
While applying the PSU we let user know about any patch conflict or overwritting any patch. For some reason if u decide to apply old PSU patch- 17513525 on 18.104.22.168 OMS then you can look at the readme of the patch to see the list of bugs fixed.
refer: Oracle Recommended Patches (PSU) for Enterprise Manager Base Platform (All Releases) (Doc ID 822485.1)