must be/must have is used to show that we are sure that something is true and we have reasons for our belief.
He looks happy, he must be hearing good news
Note that be requires an adjective or noun to follow it, not a verb, so we use a kind of adjective called an active participle hearing. Together with be, this forms a present continuous.
He looks happy, he must have heard good news
Have must be followed by a past participle or by been and a present participle. In this case, the past participle is added, and have heard makes present perfect simple.
In these examples, we state that the reason for our belief is that he looks happy now, but we would need additional information to decide which example is appropriate. The first would be appropriate is he didn't look happy a minute ago but now somebody is talking to him. The second would be appropriate if nobody is talking to him right now but, for example, he has just come out of the boss's office after his salary review.
We cannot directly build a future for this example, as he does not yet know that he will receive good news and so he probably does not look happy, and so we cannot base our belief on the way he looks.
Here is a different example where we can infer a future event from current information:
The blackbirds are singing: it must be going to rain.