A part of the UVM "philosophy" is that vendors promote and use the same library, but they differentiate on tooling around this library. To this effect, vendors usually provide UVM debug capabilities into their tools, including support for showing which sequences are running. You'll have to look in your vendor's user manual to find relevant information.
You can still get a list of which sequences are running on a given sequencer with good old fashion debugging, by inspecting each sequencer's internal variables. You'll have to figure out yourself which ones those are. There might also be something akin to a get_running_sequences() method, with which you could obtain this information in your own code and process it to print out debug information.
