Both sides of a voltage level shifter connected
Per the datasheet:

VIH High-level input voltage, A-Port I/Os:
VCCA (V) = 1.2 to 1.95, VCCB (V) = 1.65 to 5.5 :Max Vin = VCCI
VCCA (V) = 1.95 to 3.6, VCCB (V) = 1.65 to 5.5 :Max Vin = VCCI
VCCI is the VCC associated with the data input port.

:

The TXS0108E device is a directionless voltage-level translator specifically designed for translating logic voltage levels.
The A-port accepts I/O voltages ranging from 1.2 V to 3.6 V. The B-port accepts I/O voltages from 1.65 V
to 5.5 V

:

Each A-port I/O has a pull-up resistor (RPUA) to VCCA and each B-port I/O has a pull-up resistor (RPUB) to VCCB.
RPUA and RPUB have a value of 40 kΩ when the output is driving low. RPUA and RPUB have a value of 4 kΩ when
the output is driving high. RPUA and RPUB are disabled when OE = Low.

So I would suggest just grounding the pins if they are not being used.