Write if-else condition agular 4 for flexGrow

in my app I am using fexbox concept to show the copanies name and headcompany of a material. I used ngx-datatable here. I set columnmode to flex. Now I set flexgrow for each column to 1. I want to wrote an if-else condition in case of flex-grow for this two column. for example if selectedCompany is pressed the second column grow will be 2, else it will be 1. I am very new in angular. I tried in many ways but could not achieve any result.

<ngx-datatable *ngIf="companies && companies.length" class="material" [scrollbarH]="true" [rows]="companies" [externalPaging]="true" [externalSorting]="true" [count]="companyPage.totalElements" [offset]="companyPage.number" [limit]="companyPage.size"
                        [columnMode]="'flex'" [footerHeight]="'auto'" [headerHeight]="'auto'" [rowHeight]="'auto'" (page)='onCompanyPageEvent($event)' (sort)='onCompanySortEvent($event)' (activate)="onActivateCompany($event)">
                        <ngx-datatable-column [prop]="'name'" [flexGrow]="1" >
                            <ng-template ngx-datatable-header-template >
                                        <span class="ellipsis" title="">
                                                A921Name
                                        </span>
                            </ng-template>
                        </ngx-datatable-column>

// I triesd to write if-else here

                        <ngx-datatable-column [prop]="'parentName'" *ngIf="selectedCompany"  [flexGrow]="2" [sortable]="false"  >
                                <ng-template ngx-datatable-header-template>
                                        <span class="ellipsis" title="">
                                                A922ParentCompany
                                        </span>
                                </ng-template>
                        </ngx-datatable-column>
                </ngx-datatable>