WordPress MU Site's backend not opening

i have setup wp multisite to sub directories…i have created one site…when i click on the site i am taken to https://www.domain.com/folder but when i click on backend it goes to https://www.domain.com instead of https://www.domain.com/folder/wp-admin/

Can anyone tell me what did I miss ?

I have following each and every step while configuring network as well as used the domain mapping plugin.