Step 1: Go to Google Maps from the following link : Click Here 

Step 2 : Click over a red button with label “+ CREATE A NEW MAP

Step 3: A map would show up with a white panel on the left-hand side, check the details in the white panel. 
Step 4 : Fill the White Panel with details you would like to include in the map to the viewer as the following image. 
Step 5: Import the data, in this example, would import data from google sheet which shared in the drive. 

Step 6 : The data will be retrieved and will pop up a couple of dialogue box, first one would request to choose columns to position your placemarks, so select the column title with country or city details and then click on “continue

Step 7: After that would request from you to choose a column to title your markers, so select the marker title which you would like to be shown to map viewer. 
Step 8: the data will be retrieved into the map, but would be all in same colour and shape of the marker. In this step, you would Click over “Uniform Style” link 
Step 9 :  After Click uniform style a mini pop up window with two drop-down boxes, 
  1. the first one with title “Group places by ” : Select the filter or field which divide the marketplace with 
  2. The second would be set labels: so you may choose the label from the drop-down list too. 
Step 10: close the pop-up window and in this step you free to share, preview and embed the map as you would like.