In Google map Custom fields are used to display infowindow contents of the posts.Custom Fields are associated with Posts. You can create unlimited custom fields and display them in info window. To add multiple ‘Custom fields’ you should do following steps :

Show Post Infowindow using custom field

Step 1 It is hidden by default and you need to use the screen options at the top of the posts/pages and enable ‘custom fields’.

How to show post info window using custom field Wpmapspro

After that, the box appears at the bottom of the editor screen.

Custom Field Box Wpmapspro

Step 2 Here, you can easily add any custom field you like. All you need to do is give it a name and a value.

Add Custom Field Wpmapspro

Step 3 Go to Add or Edit Map page and scroll down to ‘Infowindow Message for Posts’ and insert custom Fields placeholder.
* Use {%custom_field%} to display custom fields, in the infowindow content. In this e.g You can Use custom field as a placeholder like {%phone%},{%website%} etc. You can use your own html structure as well.

Infowindow Message Post Wpmapspro

Step 4 Click Save Map and open it in browser.
Your Post infowindow looks like :

How to show post info window using custom field Wpmapspro

Video Tutorial