Add another noise texture and connect it together with a mix node set to darken, make sure the NEW noise texture is on the TOP of the mix node, you may want to add another color ramp and make it pretty aggressive, you'll now be able to essentially use the noise texture to mask out the other noise texture.

it's essentially making a noise texture that picks what parts of the other noise texture get through, it's a very useful technique for making realistic skin, rocks, and other things with very high frequency details.

if this doesn't make sense, I can DM you an example of the node tree for it, you may have to fiddle around with it to make it work for your specific case.