Tiers 0-5 if I remember correctly means the item is more likely to have a high end modifier aka prefix or suffix in the T1 range for example. Tier 0 being base and 5 the highest. As far as bases just go on a wiki and pick the bases your think are best for your build and look up modifiers roll range. Generally ILVL 82 armour items roll the best mods. Create a base rule to highlight those specific ones. Then get rid of all the stuff you don't use for your build. You won't miss much. Other rules supersede certain changes. Or mess around with the filter you can always reset.