How do i unlock?

They are only available in certain Riddler's Revenge Challenge Maps. You do not "unlock" these modifiers.
If you have used the modifier once when completing one tier out of the three in the map and have already used a Modifier, you will not be able to use it again for the duration of the challenge map.

Hope this helps you out and good luck

Firstly, they are available in Riddlers challenge: campaign mode; certain modifiers are allowed/have to be used in any combination within the three challenges of the campaign. You can only choose between the ones given.

Plus they are also available in Custom challenge mode; in order to use them, you have to unlock them by unlocking the campaigns (simply unlock them, you do not have to play/win them). Once you are able to select all campaigns, you should be able to use the modifiers in Custom mode.

This is only available in riddler challenge maps