By default, the platform does not have this option. You can use the following CSS code to hide/disable the Last Activity time.

Please follow the steps below:

1. Go to BuddyBoss > Theme Options

2. Under Custom Codes, enable CSS

3. Append the following:

p.item-meta.last-activity { 
    display: none;

4. Save changes.

Note: Any modifications are considered as custom work already. Know more about our Support policy here:

Without code: 

With code: