Try One Function at a time and refresh the page before trying the other function
Traversing Descendant
Refresh/Reload ||
$("div > div").slice(2, 5)  
$("div").siblings('.x1')  
0
Div1 1
Div 2
Din 3
Div 4 4
div within div : 1
div within div : 2
div within div : 3
Div 5
Div 6