By default, there isn't a specific setting to add a box with rounded corners to the Blog page content. However, the customer can use the CSS code below for this purpose. 

Please follow the steps below:

1. Go to BuddyBoss > Theme Options

2. Under Custom Codes, enable CSS

3. Append the following:

.entry-content-wrap {

    background: var(--bb-content-background-color);

    border: 1px solid var(--bb-content-border-color);

    border-radius: var(--bb-block-radius);

    -webkit-transition: all linear .2s;

    transition: all linear .2s;

    padding: 20px !important;

}

4. Save changes.

Note: Any modifications are considered custom work already. Know more about our Support policy here: https://www.buddyboss.com/support-policy/

With the Code: