Here. is very simply by which you can add auto zoom/center according to your irst latitude and longitude without fitBounds.


        var zoom = 12;
        var lat1 = '<?php echo $first_lat; ?>';
        var lat2 = '<?php echo $latitude; ?>';
        var lon1 = '<?php echo $first_lng; ?>';
        var lon2 = '<?php echo $longitude; ?>';
        var unit = 'M';
       
       

        function distance(lat1, lon1, lat2, lon2, unit) {
var radlat1 = Math.PI * lat1/180
var radlat2 = Math.PI * lat2/180
var radlon1 = Math.PI * lon1/180
var radlon2 = Math.PI * lon2/180
var theta = lon1-lon2
var radtheta = Math.PI * theta/180
var dist = Math.sin(radlat1) * Math.sin(radlat2) + Math.cos(radlat1) * Math.cos(radlat2) * Math.cos(radtheta);
dist = Math.acos(dist)
dist = dist * 180/Math.PI
dist = dist * 60 * 1.1515
if (unit=="K") { dist = dist * 1.609344 }
if (unit=="N") { dist = dist * 0.8684 }
return dist
}
var dis = distance(lat1, lon1, lat2, lon2, unit);

// change value according to your needs.

if (dis > '2.0' && dis < '3.9'){   
        zoom = 11
       
        } else if (dis > '4.0' && dis < '5.9'){
        zoom = 10;
       
        } else if (dis > '6.0' && dis < '9.9'){
        zoom = 9;
       
        } else if (dis > '10.0'){
        zoom = 8;
       
        } 



    var mapOptions = {
               center: new google.maps.LatLng(lat1,lon1),   
               zoom: zoom,
                 scrollwheel: false,
 disableDoubleClickZoom: true,
               mapTypeId: google.maps.MapTypeId.ROADMAP
           };
           map = new google.maps.Map(document.getElementById("map-canvas"), mapOptions);
           {
/*
FOLLOW YOUR OTHER MAP CODE <../> 
*/

           }

 Here is just simple code by which you can get wordpress posts in text box in autocomplete. [like search]




<?php
      // The Query
$the_query = new WP_Query( 'post_type=post' ); //Whatever your posts type.

// The Loop
if ( $the_query->have_posts() ) {
  foreach ($the_query->posts as $post_nm) {
    if($post_nm->post_title != ''){
      $post_names[] =  $post_nm->post_title;
    }
  }
}
/* Restore original Post Data */
wp_reset_postdata();

$post_names = implode('","', $post_names);
?>
<script type="text/javascript">
$(document).ready(function(){
    
    var availableTags = ["<?php echo $post_names; ?>"];  
    //console.log(availableTags);
    $('#textFeild').keyup(function(){  //Enter your text field id
         $('#textFeild').autocomplete({
             minLength: 1,
            source: availableTags
        });
    });
});
</script>
       
thanks :)

Bilal Hussain | Get post’s arguments on text input – autocomplete | wordpress