In Sierra there was All My Files in your Finder> Preferences> Sidebar> Favourites, in High Sierra this was replaced with Recents,
and continues in Mojave.
There is a possible way to make a Smart Search folder for that searches for recent items.
In Finder click on File and New Smart Folder. A new Finder window will open.
Make sure This Mac is highlighted, on the right hand side click on the + button
now you can now select the criteria to narrow your search,
start with Kind is Any press the plus again add more criteria try
Last modified Date is Within Last 30 days
you can choose whatever search criteria in the fields and as as many you like.
Under Other... there are more selections you can make. Once you are satisfied
click to Save your Smart Search Folder, give it an appropriate name.
Make sure Add To Sidebar is selected. you can click the downward pointing arrow in the dialogue to expand the Save As window to show the folder structure of your Mac and select your own destination for the folder rather than the default Save Searches folder.
Experiment.