Use the below code to get the Logged In User Security Role Names in Dynamics 365 V9.X,

JS Code:

function GetLoggedInUserSecurityRoleNames() {
 // Get Logged In User Context
 var userSettings = Xrm.Utility.getGlobalContext().userSettings;
 // Get Logged In User Security Roles
 var loggedInUsersecurityRolesGuidArray = userSettings.securityRoles;
 var totalSecurityRolesArray = new Array();
 var rolesOutputText = "";

if (loggedInUsersecurityRolesGuidArray.length > 0) {
 Xrm.WebApi.retrieveMultipleRecords("roles", "?$select=name,roleid").then(
 function success(result) {
 if (result.entities.length > 0) {
 // Push Role Names and Role Ids to Array
 for (var rolesCount = 0; rolesCount < result.entities.length; rolesCount++) {
 totalSecurityRolesArray.push({ RoleName: result.entities[rolesCount].name, RoleId: result.entities[rolesCount].roleid });
 }

rolesOutputText = userSettings.userName + " has the below Security Roles\n------------------------------------\n";

// Compare the User Security Roles with Total Security Roles
 for (var userSecurityRolesCounter = 0; userSecurityRolesCounter < loggedInUsersecurityRolesGuidArray.length; userSecurityRolesCounter++) {
 for (var totalsecurityRolesCounter = 0; totalsecurityRolesCounter < totalSecurityRolesArray.length; totalsecurityRolesCounter++) {
 if (totalSecurityRolesArray[totalsecurityRolesCounter].RoleId.toLowerCase() == loggedInUsersecurityRolesGuidArray[userSecurityRolesCounter].toLowerCase()) {
 rolesOutputText += totalSecurityRolesArray[totalsecurityRolesCounter].RoleName + "\n";
 break;
 }
 }
 }
 }

// Show User Roles
 Xrm.Utility.alertDialog(rolesOutputText, null);
 },
 function (error) {
 // Show error
 Xrm.Utility.alertDialog(error.message, null);
 });
 }
}

Output: Have configured the above function on Onload of Account and below is the output.

Hope you got all the Security Role Names of the Logged In User :):):)