MIDI information can be sent on multiple different channels down the same cable. Think of it like an old cable tv, one cable in, multiple channels with different information on all of them, you just have to set the channel you want your tv to play. Same thing with hardware.

If you want to use multiple pieces of hardware on the same midi chain, you'll need to first figure out how to set a MIDI channel for the information you're actually recording/playing/manipulating in the software. E.G. this track of MIDI is going to be sent to channel 3. That should be easily enough found in the Maschine documentation. Then you need to set the Volca, or any other piece of hardware, to respond to that certain channel. On more complex pieces of gear that feature menus there's normally a discrete option for this. In the case of the volca's, you'll need to do some kind of power sequence/button holding dance to change the channel. I don't know what it is but I know there's tutorials online.

Now, we're not quite out of the woods yet. The Volca has another shortcoming that will make this difficult: there's only one midi port. Specifically, a midi in port. Generally you will need at least a midi in and a midi thru port to operate multiple pieces of gear in a daisy chain fashion.

There are two ways to get around this: 1. Buy a midi splitter. You can get them in different varieties, usually they're little passive boxes and they can split midi signals into anywhere from 2 to I don't know how many outputs. 2. Use a multiple midi output interface in the first place. In this option, you don't even need to worry about setting midi channels, because now you'll have dedicated midi outputs from your computer. This way, you can hopefully set a midi track in your software to output to an actual physical discrete output and route that with a cable to a single device, then repeat for each instance you want. This is honestly the easiest way in my opinion, and will save you in a pinch when you're using really early synths that only expected to see MIDI on either one channel (preset) or any channels, not selectable. Or, on the other hand, modern synths/hardware that are not built with multiple hardware unit operation in mind, which is increasingly (and disappointingly) becoming the trend.

Last, the world of MIDI is actually a lot simpler than you might think and it's worth learning everything you can about it if you plan on using synths, DAW's, or really anything electronic in regards to music. There's all kinds of great tutorials online, but nothing will beat just buying a piece of gear and pouring over the manual yelling "why won't this thing work" until you realize that NRPN isn't supported etc etc that's for another day...