Maintaining page hierarchy in URLs

I am new to WordPress and have postname checked under Permalink Settings:

/%postname%/

However this seems to not take any notice of the page hierarchy set up in the main menu.

For example I have an Immunisation page and I then have Influenza and MMR as two sub pages of that page set up in the main menu. However each page is just linked to the root by its slug name:

www.website.com/immunisation/ 
www.website.com/influenza/
www.website.com/mmr/

But I would prefer to maintain the hierarchy setup within the URL itself, ie:

www.website.com/immunisation/
www.website.com/immunisation/influenza/
www.website.com/immunisation/mmr/

What is the easiest way to achieve this? I tried just editing the slug for the page to be eg immunisation/influenza/ but it auto converts the / to a – which I don’t want. There must be a way to do this as I would think its pretty basic SEO building. I dont really want to hack the site code at all either as hopefully that shouldnt be required.

Any help much appreciated.

• This topic was modified 2 years, 7 months ago by Jan Dembowski. Reason: Moved to Fixing WordPress, this is not an Developing with WordPress topic