In the advanced filter box you can chain multiple filters to select the units you want (like all the units with issues in a certain location)
The unit is mining properly without problems
The unit has one or more problems (not all hashing boards online, temperature above threshold, hash rate below threshold)
The unit has been initially recorded into the database but has yet to go online for the first time. These units are not being listed in the units view per default. You can choose to do so by unchecking the box ‘Exclude units marked as “ready”’ above the units list.