Sample code:


Component:

1. <aura:component implements=“lightning:recordHomeTemplate”>  
2.       
3.     <aura:attribute name = “left” type = “Aura.Component[]” />  
4.     <aura:attribute name = “middle” type = “Aura.Component[]” />  
5.     <aura:attribute name = “right” type = “Aura.Component[]” />  
6.       
7.     <table>  
8.         <tr cellpadding = “8” cellspacing = “8” style=“vertical-align:top;”>  
9.             <td width=“14%”>{!v.left}</td>  
10.             <td width=“1%”></td>  
11.             <td width=“45%”>{!v.middle}</td>  
12.             <td width=“1%”></td>  
13.             <td width=“39%”>{!v.right}</td>  
14.         </tr>  
15.     </table>  
16.       
17. </aura:component>  

Design:

1. <design:component>  
2.       
3.     <flexipage:template >  
4.           
5.         <flexipage:region name = “left” defaultwidth = “Medium”/>          
6.         <flexipage:region name = “middle” defaultwidth = “Medium”/>          
7.         <flexipage:region name = “right” defaultwidth = “Medium”/>  
8.           
9.     </flexipage:template>  
10.       
11. </design:component>  

Output: