Filter with numbers and symbols

You say you have 4 types of data but not sure what those are. I see blank, numbers, number ranges (x-x), number+, number- (for an entry like 40- I assume it is basically 0-40 assuming 0 is the minimum)
You don't say what kind of filtering you want. but I'll assume some sort of number range. because if you just want to filter for any row that has a particular value in it then you can use the text filter.
So my best suggestion is to create 2 helper columns for Min WA and Max WA and then filter on those columns. Formulas for those columns might be:
Min WA: =IFS([WA]="","",ISNUMBER([WA]),[WA],RIGHT([WA])="+",--LEFT([WA],LEN([WA])-1),RIGHT([WA])="-",0,1,--LEFT([WA],FIND("-",[WA])-1))
Max WA: =IFS([WA]="","",ISNUMBER([WA]),[WA],RIGHT([WA])="-",--LEFT([WA],LEN([WA])-1),RIGHT([WA])="+",100,1,--RIGHT([WA],LEN([WA])-FIND("-",[WA])))

sry for the edit but had a typo and also wanted to mention this assumes a min of 0 and max of 100 but you could easily substitute sufficiently small and large numbers instead (e.g. 1e-99 and 1e99)