espocrm-base/application/Modules/Crm/Metadata/viewDefs/Lead.json

{
   "viewMaps":{
      "detail":"Crm:Lead.Detail"
   },
   "recordViewMaps":{
      "detail":"Crm:Lead.Record.Detail"
   },
   "bottomPanels":{
      "detail":[
         {
            "name":"stream",
            "label":"Stream",
            "view":"Record.Panels.Stream"
         }
      ]
   },
   "sidePanels":{
      "detail":[
         {
            "name":"activities",
            "label":"Activities",
            "view":"Crm:Record.Panels.Activities"
         },
         {
            "name":"history",
            "label":"History",
            "view":"Crm:Record.Panels.History"
         }
      ]
   },
   "menu":{
      "list":{
         "buttons":[
            {
               "label":"Create Lead",
               "link":"#lead/create",
               "style":"primary",
               "acl":"edit"
            }
         ]
      }
   }
}