Here are two methods which will help you in adding multiple posts under different pages in blogger.
One is the old method and the other one is the new method.
Method 1 (Old Method)
1. Go to main window of your blog. There in the left side you can find “Layout”. Click the Layout Menu.
2. Now you can see the layout of your blog. There you can find “Pages” gadget.
4. Give your page a label name. You can give the page url as external page or you can point out to Label URL.
5. That’s it. Now just repeat the same steps for creating different pages. When you write a new post you just need to enter the same label name in which you want that post to be.
Note:– This Method may not work in your case, because many times bloggers use 3rd Party Templates which do not have the pages widget installed. So, you will not find a way to add Posts under pages or in the Menu section. But the below given “New Method” will surely work with all templates.
Method 2 (New Method)
1. In the main Window, Click at “Template” from the sidebar menu and then click at “Edit HTML”.
2. Now, You will see a bunch of coding. Search for “Main Menu” or “Main-nav-Menu” using Ctrl+f. This code may occur 2 or 3 times. You need to find the menu section as given below in the screenshot.
3. Once you able to find the exact or something like” <ul><li></li></ul> coding, you can add you custom posts as given in the screenshot and you are done.
Done? If you have any queries, ask me in the comment box.