Can I make a customer Filter to display MAX date only?

[WChepe]

Hi!
I have restricted access to looker, basically, I can use the dimensions and measures available without modifying them or adding new ones, so I have a Look for chat conversations and I have a dimension for the Chat Date, then I have a dimension for Message Sent including minutes and seconds and now I would like filter the latest message sent only but I don’t know-how.
I have the Chat identifier, agent name, and message time like this:

And want the Custom Filter to hide all but the last one in the series
Can it be done?