With both your Nikon D7500 and the Panasonic FZ300 bracketing can occur one exposure per shutter release press, and any remote will work for that. With the Nikon you just use the basic BKT button/mode (and step settings) **and the shutter release set to single shot mode. And with the Panasonic you set it to "Single" in the Auto Bracket menu.
(**unless you are really good at controlling the number of shots in continuous mode)