If you refer to "Hub" as a Repeater ("Repeating Hub") as defined by 802.3 Clause 9 and Clause 27: No.

The reason is simple: Hubs work on the Physical Layer as defined by the 802 Reference Model or ISO/OSI Layer Model ("Layer 1").
The MAC, which is located in the Link Layer ("Layer 2"), sees all devices connected to a Hub as connected to the same medium.
This in turn means, that the MAC has to take care of sollisions, for Ethernet this is using the CSMA/CD algorithm.
In short it works like this: If it detects a colision, it stops sending, wait's a random time and starts sending again.

Apart from the fact that it's quite hard to find a Hub in 2021, this technology is completely diametral to the goals of Audio Networks and especially AVB: deterministic, reliable and low latency transfer of media data.
That's why shared medium/half duplex modes are not allowed in Ethernet AVB (see 802.1BA-2011 table 6-1).

In theory you could passively split the Cat5 cable into 2x2 pairs, which allows to transfer 2x 100 MBit/s. But then again, how to connect more than one Millenia? And on the other side of the cable you would need another ethernet interface to connect it to the PC. And you lose so much AVB bandwidth, that it's just not worth the hassle.

So, no, I don't see an option to do it passively. The easiest way is to buy an AVB switch (there is a very solid one with builtin PSU and PoE for below 400€). Plus, you're well equipped if you want to extend you system in the future.