You can select the head of the post(‘page parent’) in the side bar (under page attributes) when creating a new post.
https://codex.wordpress.org/Pages#To_create_a_subpage
Change the head to page1 for example to make the new post a sibling of page1.
You can select the head of the post(‘page parent’) in the side bar (under page attributes) when creating a new post.
https://codex.wordpress.org/Pages#To_create_a_subpage
Change the head to page1 for example to make the new post a sibling of page1.