Design.file

<design:component label="CustomSearch">
    <design:attribute name="name" label="Name" />
    <design:attribute name="autoInitialize" label="Auto Initialize" />
    <design:attribute name="autoInjectBasicQuery" label="Auto Inject Basic Query" />
    <design:attribute name="autoInjectBasicOptions" label="Auto Inject Basic Options" />
    <design:attribute name="debug" label="Debug" />
    <design:attribute name="searchHub" label="Search Hub" />
</design:component>

sampleCoveoWrapper.cmp

<aura:component implements='forceCommunity:availableForAllPageTypes'>
    <aura:attribute name="name" type="String" default="communityCoveo" access="global" />
    <aura:attribute name="autoInitialize" type="Boolean" default="true" access="global" />
    <aura:attribute name="autoInjectBasicQuery" type="Boolean" default="true" access="global" />
    <aura:attribute name="debug" type="Boolean" default="false" access="global" />
    <aura:attribute name="autoInjectBasicOptions" type="Boolean" default="true" access="global" />
    <aura:attribute name="searchHub" type="String" default="" access="global" />
    <CoveoV2:Search name="{!v.name}" autoInitialize="{!v.autoInitialize}" 
                    autoInjectBasicQuery="{!v.autoInjectBasicQuery}"
                    debug="{!v.debug}"
                    autoInjectBasicOptions="{!v.autoInjectBasicOptions}"
                    searchHub="{!v.searchHub}"
                    customScripts="{!$Resource.YourStaticResource + '/YourStaticResourceFile.js'}"/>
</aura:component>

YourStaticResource.js

/*This script assumes you have a CoveoFacet wiwth an id `sourceFilter` */
window.coveoCustomScripts['default'] = function (promise, component) {
  const root = document.querySelector("#search");
  const sourceFacetValueCaption = {
    "ohclouden" : "Online Help - Cloud",
    "Confluence - Developers" : "Developers",
    "Web Scraper - AnswersCloud" : "Answers",
    "Web - TechBlog" : "Technical Blog",
    "Web - JsSearchRef" : "JavaScript Search Components"
  };
  Coveo.options(root, {
    sourceFilter : {
      valueCaption : sourceFacetValueCaption
    }
  });
}