If you want assistance, this is not the way to get it.
As kennybobby pointed out, there are two categories of high voltage cables in an EV: the DC link between the battery and motor (and other devices), and the 3-phase set between inverter and motor. Because you used the phrase "to connect my motor" the meaning was not clear and clarification would help, although I suppose that you are lumping the inverter in with the motor, and you are talking only about the DC link.
In a Tesla the 3-phase wiring does not appear to be shielded, but it is internal to aluminum drive unit cases. And yes, we understand what shielding is for - the question would be why you think shielding is needed in this particular case, because if you understand the purpose you have a better chance of understanding the design.
For your DC link connecting the shield around the B- cable to B- at both ends would make the shield completely pointless - it would simply be part of the conductor. Connecting that shield at only one end to the potentially noisy voltage source would make it an antenna. Assuming something other than complete stupidity by the designer, the shield would presumably connect to a chassis or component case ground, rather than B-.
Here's an example of shielding practices in VFD's - note that shields are connected to equipment chassis/cases and to a ground reference (in a vehicle, the chassis ground would be the equivalent):
VFD Series: How to Connect the Shield in VFD Cable
In general in EVs, the high voltage system is floating - neither B- nor B+ is connected to a chassis or case ground, and both are disconnected from everything else by contactors and service disconnects. Using either as a shield wouldn't make sense. If you look at the construction of a shielded HV single-conductor cable, the thick insulation is between the conductor and the shield, not between the shield and the outside, so the shield cannot be connected to anything which could possibly be at high voltage. If the B- could not be at high voltage, if it were not a floating point, then it wouldn't need insulation at all - just like a bare ground strap in a conventional car - but in fact it is bright orange and insulated for high voltage exactly like the B+ cable. I can't image how it could be acceptable to attach a shield to it.