how to hide

Hi there,

Try this CSS:

.comments-area .comment-content {
    border: none;
}

Adding CSS: https://docs.generatepress.com/article/adding-css/

Let me know if this helps :)

NO, refer to snapshot again shared previously, what I am asking to hide, (that extra border which is visible in left and bottom)...

Your css hiding the entire border...

Try this:

.comments-area .depth-1.parent>.children {
    border-bottom: 0
}
.comments-area .comment .children {
    border-left: 0;
}

Thanku Leo

No problem :)