You are using SAP NetWeaver Identity Management 7.2 with Microsoft SQL Server as the database system and with full text search enabled. In the Role Asignment Request user interface you try to find a role where the name includes the text "only" by entering "only" in the Find field.
Depending on the version of Microsoft SQL Server used in your Identity Center, there is a stop word list containing words that are not indexed and are therefore not included in searches. If you are using just one of these words in your search, there will be no result.
Troubleshooting, IdM, reserved keyword
Configure the stop word list according to your needs.
See the documentation at SAP NetWeaver® Identity Management Identity Center: Installing the database (Microsoft SQL Server)Version 7.2 Rev 6.