Here's an easy method to separate mixed terrestrial Utricularia. It's especially helpful when weedy plants like subulata and bisquamata have infested a pot of other Utrics. I started using this to separate Utricularia colonies which come in from nurseries, where subulata and bisquamata are common weeds. The only trick is that you'll have to wait for the Utric you want to separate to flower.
When your intended plant sends up flower scapes, let them get good and big. For a lot of Utrics, they'll put on several flowers per scape. You may want to mark your targets with pieces of tape, in case the flowers drop before you can get to them. Grab each scape near the base, and gently tug it from the growing medium. Most of the time, you'll get a bit if white tissue at the base. If you're really lucky, you'll get a few attached stolons and nodes. Gently rinse the pulled flower scapes in tap or distilled water to separate any unwanted weed seeds and plant material.
Prepare a pot of fresh growing medium. Use a toothpick to make a narrow hole for each pulled flower scape. Gently push the scapes into the holes, to a depth close to their original growing depth. Use the toothpick or a spray bottle to push the potting medium around their bases, making sure not to damage the new "plantlets." Within a few weeks to a few months, you should start to see new stolons pushing up through the potting medium. I sometimes get as much as 50% die-off, but there's usually enough growth to start a whole new colony of the desired plants.
I've used this with great success to separate U. livida, U. bisquamata, and U. pubescens. Trials will woon be underway on U. microcalyx. Thanks for reading. Best of luck!