As stated, that bass has a preamp.
Trying to do it passively is rather problematic. Firstly, you can only cut frequencies, rather than boost. Second, there tends to be volume drops and weird behavior when using the controls.
Treble cuts are typically done with standard tone control wiring.
Bass cuts are typically done by placing a capacitor in series with the signal path, and using a pot to vary the resistance across the capacitor. Low frequencies are blocked by the capacitor, but the pot allows you to add them back, at an adjustable level.
Mid cuts are typically done in the same fashion as standard tone controls, but there is an inductor added in series with the capacitor, to block high frequencies from being able to shunt to ground. This, combined with the capacitor that blocks low frequencies, allows only a certain window of frequencies to be shunted to ground.