It's possible to do this, depending on how much time you have. It's not something I've tried and it seems a bit of a faff, but I think your routine would be something like this:
First of all, work out exposure times for each image; you'll need to know exactly how you want to expose each negative before you start.
Make yourself a template in card the same size as your paper. Mark out the positions of the exposures then cut apertures slightly larger than each of your planned exposures. Tidy and raggedy bits.
Make sure you have enough space both sides of the enlarger to accommodate your baseboard, which you'll need to slide across.
Make sure your baseboard, template and photographic paper won't slide across each other while you're working.
Under the enlarger, use the template to align aperture 1 for the first exposure, then place the photographic paper on your baseboard under the template. Check alignment using your red or orange swing-filter. Use another sheet of card to cover apertures 2 and 3 so the paper doesn't catch any stray light.
Uncover aperture 1 and make your first exposure, then cover aperture 1 with card. Slide the baseboard across and change the negative to set up the second exposure; you shouldn't need to refocus if you're using the same magnification and/or crop. Slide aperture 2 under the enlarger, uncover the paper and align the exposure using a red or orange swing filter to avoid exposing the paper. Make the second exposure in the same way, then repeat the sequence for the third exposure.
Once you've done this a few times, you'll get into a routine and it should become easier. Personally, I'd take the suggestions of making individual prints and presenting them together behind a single mat; but then I'm quite lazy!
Good luck.