is the link between two hubs or (communication nodes)connected together is considered multipoint and each hub connected to many devices as the data of many users are shared either spatially or temporally on this link ?
This is mostly a semantic problem. From a physical point of view, most connections you will see are point to point -- there are very few physical multipoint media types (I would propose they are all obsolete). From a logical point of view, however, many technologies act a a multipoint networks, where any endpoint can directly address another at the data link level.
It is a point-to-point link. As Ron pointed out, logically it is a semantic problem and physically a media issue which does turn out to be a logical issue in the case of a bus network, as explained by Mike Pennington♦.
However, point-to-point and point-to-multipoint are not obsolete terms when it comes to telephony. P2P connects the gateway to a single telephony system and P2MP to one or many phones. Why do I mention this? Because a gateway having more than one voice port logically acts as a hub, if it is set to forward inbound calls to each port (hunt group / ring call). Physically it does not.
With regards to your comment at Mar 31 at 15:48, yes, the link is not dedicated to a single device connected to a hub. But this is not a criterion for calling the link P2P or P2MP. A hub regenerates the incoming signal on each port, one incoming signal at a time. There is no multiple signaling at a time on the same link. In short, it's P2P, both physically and logically.