The keywords an Attendee uses to filter Sessions come from Session Keyword (conference360__Session_Keyword__c) objects. A Session Keyword object links a Keyword (conference360__Keyword__c) to a Session.
Add the Session Keywords Related List
Click the Object Manager tab.
In the Quick Find box, enter and click “Session.”
Click the Page Layouts tab.
Click the layout you want to update.
Click the Related Lists tab.
Drag and drop “Session Keywords” onto the page layout.

Click Save.
Create a Session Keyword
Open a Session record.
Click New in the Session Keywords Related List.

Select a Keyword.

If you need to create a new Keyword, click into the Keyword field and select + New Keyword.

Enter a Keyword.
Enter a Category, if using.
Click Save.

Click Save.
You have now created a Keyword and a related Session Keyword.