I haven't actually done all of this but have a basic understanding of how. Depends on if you want to look at individual players or the entire pool as a whole to get an idea of general population tendencies. From just having a quick look this is what I have kind of figured out, maybe someone else has something faster or better.

If you want to look at an individual opponent, then just click on your hero icon and choose select player. type in the name of the villain, or you can click the hand column and put the villains in order of how many hands you have on them and select a villain that you have a bunch of hands on. Once you select that villain they are basically being looked at as the Hero on HM2. You will be seeing all the hands you have on them and all of their stats.

Once there you can click on filters. There are about 7 different sections of filters (basic, hole cards, board, hand value, advanced action, bet size, other). You can go to the bet size section and HM2 will allow you to choose a street, what type of bet, how big. For example you could select: Flop; made bet; bet size. Then below it has option of doing greater than, less than, equal to or between and then what percentage of the pot. With that simple filter you would be able to see all the hands that the player you NOW selected had bet the flop at whatever size you indicated. You could use other filters to then narrow things down. Like in the basic section under common filters you could set the saw showdown to yes, then it would only show you hands that went to showdown with the previous parameters.

If you want an entire population I don't really know how to do it or sure. I think you would have to create an Alias and then start adding all of your opponents to that alias. Then you could select that alias as the player you wanted to view and it would pool all the hands and data of all the players you put in that alias together. Then you could repeat above to start seeing what people are doing with bet sizes. Easiest thing might be to choose the top 20 or 30 villains that you have the most hands on. Like villains that you have 1K or more hands on. If you have 20 or 30 of those then you could potentially have 30K-50k hands, so as you filter for stuff you will have way more instances of something occurring for the data to be more reliable. I actually did this when I was playing on Party to find out if the regs on fast fold at Party were folding to steals too much and if I could start stealing more from BU and SB vs them and what steal sizes were best.

There is also a vsPlayer tab that you can add. I have never used it and don't know what it can do for you, but you could check that and see.