This question has been asked before:
"I have a few unread messages among my dozens of Slack channels.I click one my channels to read the new message there. I quickly remember I need to respond to something on a different channel so I jump there and send the response.But now I've forgotten which channel I was on just before this, and the channel name isn't bolded anymore.How can I see a list of recent channel activity, chronologically?"
The best answer is to search for:
before:2021-09-17 after:2021-06-16
which is tomorrow's date and three months ago. Also one should add the "Only include channels I'm in" under more filters.
But this is a bit of a fiddly thing to have to do each time.
Can I save this search somewhere? Frankly I'd just always want to view slack this way. I seem to lose notifications all the time.